Developing alternatives to fossil fuels has long been a worthwhile and valuable goal, especially as obtaining sufficient fossil fuels to meet rising demands promises to become a substantial challenge. Thus, there is a growing demand for biofuels. The U.S. Department of Energy has a set a goal of meeting 20% of U.S. gasoline demand with biofuels, primarily ethanol, by the year 2020.
In 2006, it was predicted that large quantities of ethanol would be produced in the future because of two federal actions. The two actions are (1) requiring that 7.5 billion gallons of “renewable fuel” be used in gasoline by 2012 (Energy Policy Act (EPACT 2005)) and (2) providing a $0.51 tax credit per gallon of ethanol used as a transportation fuel. As expected, there has been a rapid increase in construction of bio-refineries in the U.S., resulting in achievement of the 8-billion-gallon goal by 2007. These fuel production techniques rely on corn as a feedstock, but these practices are not sustainable.
There are a number of problems with relying on corn as a major source of bioenergy. Corn grain used as a feedstock accounts for the vast majority of ethanol, but there are competing uses (food and feed vs. fuel). The production of enough corn to produce the necessary biofuel is simply not sustainable economically, environmentally, or energetically. Proponents suggest the use of corn stover, which is the residual plant material after ears are removed, can overcome some of these sustainability issues. Unfortunately, this has not been the case.
Government incentives are shifting away from biofuel techniques that rely on corn grain as a feedstock. For example, in the latest Farm Bill, the corn-ethanol subsidy went from $0.51 to $0.45/gallon, and cellulosic ethanol subsidy of $1.01/gallon was instituted. It is clear that a variety of cellulosic feedstocks will be needed.
Thus, there is a need for new bioenergy crops that are sustainable.